Caloric Balance

“Calories In”: Only 3 Ways

Carbohydrates

Fats

Protein

“Calories Out”: 3 Ways You Burn Calories

1. Basal Metabolism: basic functions- just to keep you alive

• Breathing

• Circulating Blood

• Maintaining Body Temperature

• Making New Tissue

• Removing Waste Products

• Sending Nerve Impulses

Basal Metabolic Rate (BMR)

• Calories you burn every hour to keep you alive

• 60-75% of total calories you burn

(energy needs)

• Does not include: physical activity/exercise

• Warm blooded animals: “Keep fires lit all night”

BMR measured:

• Morning

• Warm Room

• Before you get

up

• After 12 hr fast

• Difficult to Measure

In General:

BMR Lean body mass

BMR Men vs. women

(more lean mass)

BMR Age

(less lean mass)

BMR Thyroid hormones

BMR Body temperature

(fever)

BMR If calorie intake low (starvation)

Homeostasis: less energy needed to maintain weight

Frustration: Trying to lose weight

“Calories Out”: 3 Ways You Burn Calories

2. Physical Activity

• 15-30% energy you burn every day

• Higher: Athletes, laborers

• Body weight calories burned with physical activity

One Hour Walk

Body Weight Calories Burned

120 pound 190 calories

180 pounds 290 calories

More energy Move heavier person

“Calories Out”: 3 Ways You Burn Calories

3. Digestion/absorption/metabolism

of food nutrients

• About 10% of calories burned/day

• To “process” food you eat

• “Thermic” effect of food

• Diet-induced thermogenesis

Calories Burned

Fat meal Energy cost

Dietary fat Stored efficiently

“Fat goes to fat easily”

Carb, protein Energy Cost

meal

“Calories Out”: 3 Ways You Burn Calories

You are in energy balance if:

Calories in = Calories burned

Food + drink in all activities (basal metabolism

+ exercise)

Energy balance: look at both sides of equation

BMI: Estimate of body fat

Category BMI

Underweight < 18.5

Normal 18.5-24.9

Overweight 25.0-29.9

Obese 30.9 & greater

BMI = Weight (lbs) X 703

(Height)2

(inches)

Correlates: body fat

Adult woman: healthy level body fat: 21-33% total weight

Adult man: 8-20% total weight

Is the BMI a good measurement?

Correlates:

• Above “30” risk type 2 diabetes, blood pressure, heart disease

• Fast food BMI

• BMI Testosterone in men

• Fruits/veggies: women BMI

waist circumference blood pressure

Vegetarian Diet

• Lower: BMI, body weight, risk obesity, heart disease, high blood pressure, diabetes & medical costs

BMI: Not Perfect

• Athletes- muscles/lean body mass

(overestimate of fat; muscle weighs more than fat)

Hulk Hogan

6’ 8” 275 pounds

BMI 30.3

obese?

BMI: Not Perfect

Based on BMI: Half NFL players would be classified as obese

BMI: Not Perfect

• Pregnancy/Breast Feeding- higher than normal body weight

• Older adults: loss muscle mass

(underestimates body fat)

• BMI doesn’t differentiate: fat vs. muscle mass

Body fat and age

BMI: Not Perfect

• Location: BMI doesn’t tell where fat stored

• Location- fat storage: genetic

Apple vs. Pear Shape

Apple pattern: visceral fat

Viscera= internal organs: fat around organs in abdomen

Fat stored around/above waist (upper body)

Easier to

Mobilize

More common:

men

Visceral Fat

Risk

Heart disease, high blood pressure, stroke, diabetes, breast cancer

Visceral fat-women after menopause

Visceral Fat

• Stress

• Tobacco

• Alcohol

Visceral Fat

• Exercise

Pear Pattern

• More fat in hips, thighs, buttocks

(below waist- subcutaneous)

• Lower risk- these diseases

Apple vs. Pear Fat Storage

Apple & Disease Risk: Measure 2 ways

#1) Waist to Hip Ratio

Waist: Find highest point- each hip bone;

Measure around waist: just above these points;

Tape parallel to floor, snug,

normal breathing

Hip: Measure circumference:

maximal width of buttocks

Example: 36 inch waist

40 inch hips W/H= 0.9

Waist to Hip Ratio

> 0.90

greater risk

> 0.80

Apple & Disease Risk: Measure 2 ways #2 Waist Circumference

> 40 inches

greater risk

> 35 inches

Skinny Person

with pot belly

> Heart Disease Risk

than person with higher BMI

Obesity Report Cards NY Times 1/8/07

• BMI 5th 85th percentile on growth charts = normal

Obesity Report Cards

One view: BMI- effective, low-cost screening; “healthy children- learn better”

Second view: Children confused, anxious about eating; overzealous school systems ?

Angry parents: “Doctor & parent should decide, not school nurse”

A B C

A: Cassie Allen, 15, “other children call her anorexic” B: Holly Berguson, 17, homecoming queen, “who you are counts more than how you look” (insulin resistant) C: Karlind Dunbar, 6, normal percentile range but “anxious about eating”

Response to new federal law: “all schools receiving $ for federally-funded school meals program” must:

Implement: wellness policy (nutrition & physical activity)

Started: 2006-07 school year

• Third View: Inconsistent message

• Blossburg, PA: 34% kindergartners- overweight; 60% eighth graders BMI > 85th percentile

• State requires BMI reports

• School cafe: funnel cakes & pizza for breakfast

• P.E. only half year

• Local pizza chain: “Pudgies”

• Local restaurant: grilled chicken salad + fries piled on

NY Times 2/8/07 “Athletes embrace size, rejecting stereotypes”

• “ Female athletes face enormous pressures: remain thin with body type unrealistic for sports”

• NCAA recommends not weighing women regularly

• Dr. Thompson (Indiana psychologist): “Weighing doesn’t accomplish anything- public degradation”

Courtney Paris: 19 year basketball center- University of Oklahoma

• 6’ 4’’ 240 pounds

• “Female Shaquille O’Neal”

• Averages: 23 points, 16

rebounds/game; 100 blocked

shots- one season

• Her dad: 3 time Superbowl

lineman

• Courtney Paris: “We’re women not apologizing for being bigger and being different or for being athletic”

• Developed skills: practice- older brothers

• Today: role models e.g. Women’s National Basketball Association- practice regularly against men